The Virtual High School
The Virtual High School project is a collaborative of high schools from around the country. In exchange for contributing a small amount of teaching time, a school in the collaborative can offer its students web-based courses ranging from advanced academic
...more>>

Weather Underground - University of Michigan
One Sky, Many Voices: resources for collaborative study of current weather events for K-12 classrooms, after-school groups, and at-home learning. Gather data on weather information on the Web, current conditions around the world, historical weather patterns,
...more>>

Which One Doesn't Belong? - Mary Bourassa
Also known as Imposter Sets, "Which One Doesn't Belong?" provides thought-provoking puzzles, each with many different, correct ways of identifying the exceptional shape, number, graph, or equation from the colorful 2 × 2 grid of similar ones.
...more>>

ZetaTrek - Rohit Gupta
An "online expedition of science and math hobbyists across the world," ZetaTrek mobilizes citizen scientists to promote the history and culture of mathematics, and involves them in research, with particular emphasis on solving the Riemann Hypothesis.
...more>>